SCIPP utilized the data archives of the United States Drought Monitor and FEMA to examine a frequency-based analysis of drought and weather-related disaster declarations throughout the contiguous United States using Geographic Information Systems. The purpose of the analyses was twofold: First, a geographic assessment of the frequency of each category of drought in the contiguous United States was performed to address several common questions that arise when a region is experiencing a drought or is attempting to plan for future water resources, such as the frequency and average duration of drought in the region. Second, a spatial comparison was made between the dual frequencies of weather-related disaster declarations and drought, placing a spatial context in the ways in which droughts compare to other weather and climate extremes. This analysis covered the 2000 – 2017 time period at roughly the county level.
During the course of the analysis, it was discovered that the Standardized Precipitation Index (SPI) used by the National Centers for Environmental Information (NCEI) differed from SPI values from other sources. The cause was found to be that NCEI uses a moving baseline whereas others used a fixed baseline, such as 1991-2020. For more information on this comparison, see the result here.
For the paper, click here.